1. Field of the Invention
The present invention relates to a light source apparatus in which a solid light emitting element such as an LED, an SLD, and an LD is used.
2. Description of the Related Art
As a light source apparatus for an endoscope, a light source apparatus such as a xenon lamp, a halogen lamp, or a metal halide has hitherto been used. However, the light source apparatus such as the xenon lamp has a large size and high cost, and a light guiding efficiency up to an irradiated light emitting portion at a front end of the endoscope is low.
With regard to such problem, a conventional light source apparatus for endoscope has been disclosed in Japanese Patent Application Laid-open. Publication No. 2006-296499. FIG. 14 is a diagram showing a cross-sectional structure of main components of a conventional light source apparatus for endoscope 500. The conventional light source apparatus for endoscope 500 has a holding member 502 which is mounted on an endoscope inserting portion which is to be inserted into a body to be checked, a phosphor 509 which is fixed to the holding member 502, a laser light source not shown in the diagram, which irradiates laser light to fluorescent bodies 509a, 509b, and 509c, a light guide 524 which guides excitation light emitted from the laser source, and a convex lens 534 which spreads the excitation light emitted from the light guide 524. This is a light source apparatus in which, the excitation light emitted from the laser source is irradiated to the phosphor 509, and the phosphor 509 irradiates light of a wavelength different from a wavelength of the excitation light, to an area to be observed of the body to be checked. In this conventional light source apparatus for the endoscope, an arrangement is made such that the excitation light emitted from an emitting end portion Po of the light guide 524 is spread by the convex lens 534, and the excitation light is irradiated to a wide area of the phosphor 509. Therefore, it is possible to emit fluorescent light from the wide area of the phosphor 509.